Preterm Birth Associated With Group B Streptococcus Maternal Colonization Worldwide: Systematic Review and...

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Infectious Diseases

Background:

• Preterm birth complications are a leading cause of mortality in children under five.
• Maternal rectovaginal colonization by Group B Streptococcus (GBS) during pregnancy is a potential risk factor for preterm delivery.

Purpose of the Study:

• To assess the association between maternal GBS colonization and preterm birth.
• To inform estimates of the GBS disease burden.

Main Methods:

• Systematic literature reviews across multiple databases (PubMed, Embase, LILACS, WHOLIS, Scopus).
• Inclusion of unpublished data from investigator groups.
• Meta-analyses to derive pooled risk and odds ratios, with sensitivity analyses for bias.

Main Results:

• 45 studies were included in the review.
• Maternal GBS colonization showed a risk ratio of 1.21 for preterm birth in cohort/cross-sectional studies (P=.061).
• Case-control studies indicated an odds ratio of 1.85 for preterm birth (P=.003).
• GBS bacteriuria was significantly associated with preterm birth in cohort studies (RR, 1.98; P<.001).

Conclusions:

• Evidence suggests an association between maternal GBS colonization and preterm birth, especially with ascending infection (bacteriuria).
• Potential biases and confounding factors may affect the observed association.
• Future maternal GBS vaccine trials should assess effects on preterm delivery.